The present disclosure relates to a thin film transistor circuit. More particularly, the disclosure relates to a display device that uses thin film transistors each having an oxide semiconductor.
Today, there are widely used circuits that adopt thin film transistors (TFTs) utilizing amorphous silicon (α-Si) or low-temperature polysilicon (LTPS) in their semiconductor layer constituting drive circuits of a display device such as an active matrix liquid crystal display or an electroluminescence (EL) display.
Meanwhile, thermal processes are indispensable for the production of the TFTs. That means it is difficult to use flexible substrates such as plastic or film substrates known to have low resistance to heat.
Under such circumstances, efforts have been underway to develop a TFT that utilizes an oxide semiconductor easy to deposit at low temperature in the channel layer (semiconductor layer) (e.g., Japanese Published Unexamined Patent Application No. 2011-91110).